There are many industrial environments where explosive atmospheres are present due to the nature of the products produced or processed. Facilities such as oil refineries, gas processing plants, grain elevators, etc. are some examples of such environments where electrical discharges must be tightly controlled in order to prevent explosions.
Over the years standards have been developed to minimize the potential for electrical discharges such as sparks or arcs in electrical products placed in environments where explosive atmospheres are present. For example Class 1 hazardous environments include those containing flammable gases, vapors or liquids; Class 2 includes combustible dusts; Class 3 includes ignitable fibers. Environments where those explosive atmospheres are sometimes present are further classified as Division 2 environments. Therefore, an environment where flammable gases were sometimes present would be considered a Class 1, Division 2 area.
As with any type of environment, lighting is an important element. Lighting fixtures in locations where explosive atmospheres could be present require lighting fixtures which are resistant to exposing electrical discharges. In other words, the lighting fixtures used for Class 1, Division 2 areas should be fabricated such that they are safe for installation in Class 1, Division 2 areas.